phenomenal development of pathology, under Rokitansky and Virchow, was Morgagni's publication in 1761 of his "Seats and Causes of Disease," the first systematic effort to correlate clinical manifestations with pathological anatomy. Likewise, the introduction by Jenner (1796) of the systematic practise of vaccination against small-pox, presaged those methods of prophylaxis which within the next century were to revolutionize the methods of controlling many of the infectious diseases. We will return in later lectures to both Morgagni and Jenner and their influence on the development of pathology and immunology, but here they serve with Hunter and Haller to illustrate how a few individuals with a genius for accurate observation, sound thinking and exact experimentation may by their contributions foreshadow the activities of a succeeding century, and be the forerunners of new schools of thought. Their labors with those of Vesalius, Paré and Harvey are examples of that effort which, isolated though it was, during the three or four centuries preceding the year 1800 and proceeding as it did from individuals living and working in widely separated places, nevertheless, constituted in the sum a sound body of knowledge readily available to future investigators, equipped with new methods. With the exception of Paré no one of these men was' thoroughly appreciated by his contemporaries. Vesalius was reviled and forced to leave Padua, Hunter's ligation of a vessel in continuity was at first ridiculed and Harvey's discovery, like others in various fields, because not possible at once of practical application, did not appeal to medical men-who still clung to the traditional teachings of Galen. It was the period of genius working alone without the approval of the profession, without the support of universities and laboratories, and without the means of publications and the means of travel that to-day render almost immediately available new advances, achievements and theories. One had to journey to the city or country of this or that authority or investigator to get his views. Merz, in his "History of European Thought in the Nineteenth Century," gives, as examples of such voyages of discovery Voltaire's visit "to England in 1728, where he found the philosophy of Newton and Locke, at that time not known and therefore not properly appreciated in France; the journey of Adam Smith in 1765 to France, where he became acquainted with the economic system of Quesnay"; and the visit of Wordsworth and Coleridge to Germany, whence the latter brought to England the new philosophy of Kant and Schelling." It is not surprising that under such circumstances advances in medicine, as in science generally, were few and far between.
How the change from individual to organized effort came about, and how medicine became the subject of investigation by scientific methods in laboratories established for that purpose will be shown in the next lecture.